Improved Treatment in a Facultative Lagoon System - Case Study
Topics: wastewater, facultative, lagoon, pond, DO distribution, odor mitigation, SolarBee floating wastewater mixers
System Overview: Wastewater influent to this system consists of ~50% municipal from the City and ~50% industrial from a local candy manufacturer.
This is a 3-cell facultative lagoon system covering a total of 102 surface acres. Water enters the system at Cell 1 then flowing sequentially into Cells 2 and 3 before being discharged. It has an operating volume of 151 million gallons and an average operating depth of ~5 feet.
Pre-Deployment Conditions: This system had serious issues with short-circuiting and poor dissolved oxygen distribution. This caused uneven total suspended solid (TSS) buildup, inefficient treatment & sludge digestion, and noxious odors in the spring.
In 2007- 2008, the City did a complete retrofit of this lagoon system which included SolarBee floating wastewater mixers. They added an equalization basin forcing diffused air into the system and modified system piping to help improve flow patterns.
Project Objectives: Improve hydraulic circulation and mixing, reduce short-circuiting and improve distribution of dissolved oxygen within the lagoon volume. Enhance suspended solids distribution and assist in sludge/slurry digestion.
Solution: A total of eleven (11) SolarBee SB10000v12-DM floating wastewater mixers were deployed in May 2007.
- Cell 1: Six (6) units.
- Cell 2: Three (3) units.
- Cell 3: Two (2) units.
Results: Since deployment, they have not had any problems meeting their TSS and BOD discharge limits of 80 mg/L and 30 mg/L respectively even with high BOD loading from the candy manufacturing plant.
Enhanced circulation & mixing have also significantly increased dissolved oxygen distribution and short-circuiting is no longer a problem. Spring odor problems have been resolved.
The City is very pleased with the sustainable water quality benefits their SolarBee floating wastewater mixers have provided. They also appreciate the high quality customer service & technical support they have received throughout the continuing life-cycle of their Medora Corporation equipment.